<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            height: 20px;
            width: 200px;
            background: #ff4400;
        }
        div >div{
            width: 20px;
            background-color: #000;
        }
    </style>
</head>
<body>
    <div>
        <div></div>
    </div>
</body>
</html>